1. Field of the Invention
The invention relates generally to the field of laser capture microdissection (LCM). More particularly, the invention relates to providing a biological sample with a polymer barrier prior to laser capture microdissection.
2. Discussion of the Related Art
LCM is a process by which cells and portions of biological tissue samples are acquired directly from tissue sections mounted on glass slides or other solid surfaces. The process involves placing a Capsure(trademark) device, containing a thin-film polymer, onto the tissue section. Once the cells or tissue portions of interest (tissue targets) are located in the sample, a laser is focused over the tissue targets. When the laser is fired, the thin-film located directly above the tissue targets melts, flows down and adheres to the tissue targets. The Capsure(trademark) device, holding the adhered tissue targets, is then removed from the tissue sample. The tissue targets are now stabilized on the Capsure(trademark) device and ready for molecular analysis.
Currently, when Capsure(trademark) devices make contact with a tissue section during LCM, the total working area of the Capsure(trademark) device touches the surface of the tissue section. Due to the friable nature of tissue sections, loose material (whole cell or macromolecular) is likely to adhere to the surface of the Capsure(trademark) device during LCM. This is known as non-specific transfer. Since LCM sample recovery involves extraction of the material on the surface of a Capsure(trademark) device, any non-specific material transferred during LCM can cause sample contamination and adversely affect the quality and accuracy of downstream analyses.
Heretofore, the requirement of reducing or eliminating non-specific transfer during LCM has not been fully met. What is needed is a solution that addresses this requirement. The invention is directed to meeting this requirement, among others.
The principal goal of the invention is to satisfy the above-discussed requirement of reduction or elimination of non-specific transfer during LCM. It was reasoned that by applying a protective barrier or coating to biological tissue sections prior to LCM, loosely adhered tissue would be retained beneath the barrier, whereas tissue targets adhered to the melted polymer would easily be removed with the Capsure(trademark) device. Another goal of the invention is to improve visualization of the sample during LCM. Another goal of the invention is to stabilize and retard degradation of biological samples being used for LCM or other types of biological analysis. Another goal of the invention is to reduce contamination of biological samples during storage before or after LCM.
One embodiment of the invention is based on a method of processing a biological sample for laser capture microdissection, comprising: providing the biological sample; and applying a substance to the biological sample so as to provide a barrier between the biological sample and a surrounding environment. Another embodiment of the invention is based on an article of manufacture, comprising: a biological sample that is to undergo laser capture microdissection; and a barrier coupled to at least a portion of said biological sample. Another embodiment of the invention is based on an article of manufacture, comprising: a portion of a biological sample that has undergone laser capture microdissection; and a barrier coupled to said portion of said biological sample. Another embodiment of the invention is based on a composition to process a biological sample for laser capture microdissection, comprising: a solvent; and solute in said solvent, said solute capable of forming a barrier on said biological sample. Another embodiment of the invention is based on a method, comprising: applying a substance to at least a portion of a biological sample that is to undergo laser capture microdissection.
Another embodiment of the invention is based on an apparatus to apply a substance to at least a portion of a biological sample that is to undergo laser capture microdissection, comprising: a container adapted to provide a fluid source of said substance, said container including an orifice that defines a principal plane that is substantially parallel to a primary direction of movement that is to be taken by said biological sample while said substance is being applied. Another embodiment of the invention is based on an apparatus to apply a substance to at least a portion of a biological sample that is to undergo laser capture microdissection, comprising: a dispensing device to deliver or apply a volume of fluid directly onto a biological sample. Delivery or application of the fluid volume to the sample can be in the form of a bead, droplet, spray dispersion, aerosol, spin-coat and/or drip-coat. Another embodiment of the invention is based on an apparatus to apply a substance to at least a portion of a biological sample that is to undergo laser capture microdissection, comprising: a release layer; and a solid layer of said substance coupled to said release layer. Another embodiment of the invention is based on an apparatus to apply a substance to at least a portion of a biological sample that is to undergo laser capture microdissection, comprising: a blade including an indexing surface and a surface to define a gap that defines a principal plane that is held at an acute angle with respect to a perpendicular to a primary direction of movement that is to be taken by said biological sample while said substance is being applied.
These, and other goals and embodiments of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the invention without departing from the spirit thereof, and the invention includes all such modifications.